another thing to consider is the baffle direction. like Paul's and my quilts, the baffles run vertically so you arent trying to force a flat piece of mesh to curve around the user, unnaturally.
personally, i tweaked my UQ to fit for the curve under the butt. at that area, most users will have a slight 3-5 degree curve from the torso and the legs. the dual differential at this point makes the quilt adapt to this curve without compression.
my summer version has only a one-way differential but it is sewn thru, so dual diff. would be impossible. still, i have taken the Breeze down to 31 degrees (to my own surprise)